You will be fine with the 9 amp intek so long as your battery is good.
When running the alternator will be able to keep up with the electric clutch but won't put much back in to charge the battery.
If you are doing 5 acres with only 4 to 10 starts a decient battery will see you through.
Just plug it into a trickle charger when you put it back in the shed.
If you are going to do a rebuild on the kawakasi over the off season you should get through with the intek without dramas.
Before you start just check the spindle diameters as they are generally 1" on domestic engines and 1.125" on commercials when you get over 20Hp